width sets the width of the element. width:auto is the default value.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title></title> <style type="text/css"> * .container { position: relative; } * .box { position: absolute; overflow: auto; visibility: visible; z-index: 1; left: 300px; right: auto; top: 0; bottom: auto; width: 220px; height: 100px; margin: 10px; padding: 10px; background: red; } * .before { z-index: 2; width: 100px; height: 400px; left: 400px; right: auto; top: 100px; bottom: auto; background: yellow; } </style> </head> <body> <div class="container"> <div>BEFORE</div> <div class="before">ABSOLUTE BEFORE</div> <div class="box">this is a test. this is a test. </div> </div> </body> </html>